/// <reference types="node" />
/**
 * A challenge issued by the server
 */
export interface CachedChallenge {
    /**
     * A key that can uniquely identify the user
     */
    userId: string;
    /**
     * The decrypted challenge nonce issued by tbe server
     */
    clientChallenged: Buffer;
    /**
     * The DateTime the request occurred
     */
    requestDateTime: Date;
}
/**
 * A cache of challenges that allows only getting the key once per set()
 */
export interface ChallengeCache {
    /**
     * @param key The key to retrieve
     * @return The cached challenge or null if the key is expired or does not exist
     */
    get(key: string): CachedChallenge | null | Promise<CachedChallenge | null>;
    /**
     * @param key The key to save
     * @param value The value to save
     */
    set(key: string, value: CachedChallenge): void | Promise<void>;
}
//# sourceMappingURL=ChallengeCache.d.ts.map